Search results for "albicans"
showing 10 items of 328 documents
Aislamiento y caracterización de ABG1, un gen esencial del hongo patógeno oportunista Candida Albicans.
2005
Mediante el inmunorrastreo de una genoteca de expresión de Candida albicans con un anticuerpo policlonal específico de la forma micelial de dicho hongo (PAb anti-gt), se ha aislado un nuevo gen de este microorganismo. La represión del gen aislado ocasionó un severo defecto en la morfogénesis de C. albicans, caracterizado por la formación de cadenas de levaduras, de tamaño decreciente en dirección al extremo apical de la cadena, por lo que el gen fue denominado ABG1 (del inglés, "altered budding growth"), en base al fenotipo de crecimiento por gemación alterado observado en las cepas mutantes para dicho gen. La secuencia de aminoácidos de Abg1p, el producto del gen ABG1, presentó los porcent…
Characterization of aCandida albicansgene encoding a putative transcriptional factor required for cell wall integrity
2003
After screening a Candida albicans genome database the product of an open reading frame (ORF) (CA2880) with 49% homology to the product of Saccharomyces cerevisiae YPL133c, a putative transcriptional factor, was identified. The disruption of the C. albicans gene leads to a major sensitivity to calcofluor white and Congo red, a minor sensitivity to sodium dodecyl sulfate, a major resistance to zymolyase, and an alteration of the chemical composition of the cell wall. For these reasons we called it CaCWT1 (for C. albicans cell wall transcription factor). CaCwt1p contains a putative Zn(II) Cys(6) DNA binding domain characteristic of some transcriptional factors and a PAS domain. The CaCWT1 gen…
The 5' Untranslated Region of the
2018
Many of the virulence traits that make Candida albicans an important human fungal pathogen are regulated on a transcriptional level. Here, we report an important regulatory contribution of translation, which is exerted by the extensive 5′ untranslated regulatory sequence (5′ UTR) of the transcript for the protein Efg1, which determines growth, metabolism, and filamentation in the fungus. The presence of the 5′ UTR is required for efficient translation of Efg1, to promote filamentation. Because transcripts for many relevant regulators contain extensive 5′ UTR sequences, it appears that the virulence of C. albicans depends on the combination of transcriptional and translational regulatory mec…
The use of trypsin to solubilize wall proteins from Candida albicans led to the identification of chitinase 2 as an enzyme covalently linked to the y…
2002
The use of trypsin to break proteins covalently linked to the yeast walls of Candida albicans released approx. 50% of the proteins, but also glucose and N-acetylglucosamine. Analysis by affinity chromatography indicated that glucose and/or N-acetylglucosamine formed part of the same supramolecular complexes with mannoproteins. These complexes would represent a new type of cell wall structuration in which beta-1,6 glucan and chitin are linked to proteins. An internal peptide from a 50-kDa protein released by trypsin was sequenced, showing 100% identity with chitinase 2 protein and 92% with chitinase 3. The electrophoretic mobility of the chitinase 2 protein was changed by treatment with Endo…
Cloning of a DNA fragment encoding part of a 70-kDa heat shock protein ofCandida albicans
1995
Immunoscreening of a mycelial expression library with polyclonal antibodies raised against mycelial cell wall resulted in the detection of a cDNA encoding a heat shock protein of Candida albicans. Sequence analysis of a 0.8-kb cDNA subclone, 2M-1, revealed an open reading frame encoding 244 amino acids. Southern blot analysis with this fragment as a probe demonstrated hybridization to C. albicans DNA. Northern analysis showed a substantial increase in 2M RNA expression levels after cells were subjected to heat shock. Western blot analysis with 2M monospecific antibodies recognized a 70-kDa protein which was present in membrane particles and cytosolic fractions.
Cloning and characterization of PRB1, a Candida albicans gene encoding a putative novel endoprotease B and factors affecting its expression
2002
Abstract Several cDNA fragments corresponding to transcripts differentially expressed under conditions that favor mycelial growth of Candida albicans were identified by the “differential display” technique. One of these was cloned and used as a probe to rescue the full gene from a genomic library of the fungus. The sequence identified a single, uninterrupted open reading frame of 1395 nucleotides encoding a putative protein of 465 residues and a theoretical molecular weight of 50.3 kDa, present in the genome as a single copy located at chromosome 2 in different strains. The gene product showed high homology with subtilisin-like proteases, mainly PRB1, the vacuolar B protease from Saccharomy…
Soft X-ray tomography of phenotypic switching and the cellular response to antifungal peptoids in Candida albicans.
2009
The opportunistic pathogen Candida albicans can undergo phenotypic switching between a benign, unicellular phenotype and an invasive, multicellular form that causes candidiasis. Increasingly, strains of Candida are becoming resistant to antifungal drugs, making the treatment of candidiasis difficult, especially in immunocompromised or critically ill patients. Consequently, there is a pressing need to develop new drugs that circumvent fungal drug-resistance mechanisms. In this work we used soft X-ray tomography to image the subcellular changes that occur as a consequence of both phenotypic switching and of treating C. albicans with antifungal peptoids, a class of candidate therapeutics unaf…
Molecular cloning and characterization of theCandida albicansUBI3 gene coding for a ubiquitin-hybrid protein
2000
Using a polyubiquitin cDNA as a probe, we have isolated a clone (pPR3, a pEMBLYe23 derivative plasmid) containing the Candida albicans UBI3 gene coding for a fusion protein. This protein is formed by one ubiquitin subunit fused, at its C-terminus, to an unrelated peptide which is similar to the ribosomal protein encoded by the 3' tail of the Saccharomyces cerevisiae UBI3 gene. Southern blot analysis of chromosomal DNA probed with the 3' non-ubiquitin tail of UBI3 indicated that only one homologous gene is present in the C. albicans genome. Heterelogous expression of pPR3 in a S. cerevisiae ubi3 mutant strain complements the mutant phenotype (slow growth) conferred by the ubi3 defect; this p…
Pga26 mediates filamentation and biofilm formation and is required for virulence in Candida albicans
2011
The Candida albicans gene PGA26 encodes a small cell wall protein and is upregulated during de novo wall synthesis in protoplasts. Disruption of PGA26 caused hypersensitivity to cell wall-perturbing compounds (Calcofluor white and Congo red) and to zymolyase, which degrades the cell wall β-1,3-glucan network. However, susceptibility to caspofungin, an inhibitor of β-1,3-glucan synthesis, was decreased. In addition, pga26Δ mutants show increased susceptibility to antifungals (fluconazol, posaconazol or amphotericin B) that target the plasma membrane and have altered sensitivities to environmental (heat, osmotic and oxidative) stresses. Except for a threefold increase in β-1,6-glucan and a sl…
The Candida albicans pH-regulated KER1 gene encodes a lysine/glutamic-acid-rich plasma-membrane protein that is involved in cell aggregation.
2004
Immunoscreening of aCandida albicanscDNA library with a polyclonal germ-tube-specific antibody (pAb anti-gt) resulted in the isolation of a gene encoding a lysine/glutamic-acid-rich protein, which was consequently designatedKER1. The nucleotide and deduced amino acid sequences of this gene displayed no significant homology with any other known sequence.KER1encodes a 134 kDa lysine (14·5 %)/glutamic acid (16·7 %) protein (Ker1p) that contains two potential transmembrane segments.KER1was expressed in a pH-conditional manner, with maximal expression at alkaline pH and lower expression at pH 4·0, and was regulated byRIM101. A Δker1/Δker1null mutant grew normally but was hyperflocculant under ge…